EPICS Channel Access UDP Processing

["Wells, Alex \(DLSLtd,RAL,LSCI\) via Tech-talk" <tech-talk at aps.anl.gov>]

Hello Tech Talk,

Could I please get some directions to the exact bit of code that processes a UDP message and iterates through the list of PVs to see if that IOC has it? I get as far as "camessage" in "camessage.c", but can't seem to find the next processing step.

I ask as I think I need to implement tracing in this function (CASDEBUG doesn't give me enough). I have one particular IOC that is regularly using 20+% CPU on the "CAS-UDP" task (as reported by "rt cpuuse"). I will note that it works fine in two other near-identical IOCs, and has also reoccurred despite replacing a lot of the hardware, so I'm currently investigating whether it's an EPICS UDP software issue.

For reference this is me continuing investigations started in this TechTalk thread: https://epics.anl.gov/tech-talk/2025/msg00318.php

Thank you,

Alex Wells

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